"Environment" research area

Improving Sulfate Removal from Wastewater at a Minnesota Power Facility

Primary Investigator - Chan Lan ChunPrimary InvestigatorChan Lan Chun
Co-InvestigatorsNathan W. Johnson; R. Lee Penn 
Industry PartnersMinnesota Power; Minnesota Department of Health; Yawkey Minerals Management
Award Type: Demonstration Grant

Problem: Elevated levels of sulfate in industrial wastewater can have adverse effects on the health of freshwater ecosystems, and thus warrants removal prior to entering the groundwater supply. Industries, utilities, and municipalities are tasked with treating their wastewater to reduce sulfate levels, but limited options exist. Current technology is commonly energy intensive and costly, which has created demand for cost-effective, flexible solutions that remove sulfate from wastewater.

Solution: Researchers have shown that bioreactors can harness the effectiveness of microbial communities in removing sulfate, but have only demonstrated this at the lab scale. MnDRIVE researchers have created such a lab-scale bioreactor that successfully utilizes microbes and mineral additives to remove sulfate from wastewater. This Demonstration Grant project team will scale up their bioreactor by partnering with a Minnesota Power facility to treat high-strength water with 800-2000 ppm of sulfate. This level of sulfate contamination is well over the recommended maximum of 250 ppm, and the volume of wastewater will be much larger than the lab-scale. This project will demonstrate the effectiveness of the bioreactor technology at realistic scales and allow researchers to determine optimal operating conditions. 

Impact: Current options for reducing sulfate levels in wastewater treatment facilities are energy intensive, generate additional byproducts, and are not very economically efficient. The bioreactor developed by MnDRIVE researchers could lead to lower maintenance costs, reduced wastewater volumes, and improved water quality. This demonstration of scalable technology will benefit both the industries that need to meet water quality standards, and the public who rely on clean water and healthy ecosystems.